Hotel chain Sheraton has announced a major revamp of its fitness offerings around the world in partnership with fitness and lifestyle brand Core Performance.

As part of the brand’s $6 billion global revitalization, Sheraton’s new Fitness Centers will feature “themed” workouts, designed to appeal to time-pressed travelers staying in the brand’s hotels.

Guests will also be able to access Sheraton Fitness online at Sheratonfitness.com, enabling them to continue their workout both at home and in hotels. The program will also include nutritional advice, which the company says is “derived from the same training methodology used by professional atheletes.”

It’s the first time that Core Performance has worked with a hotel company and is likely to provide a significant boost to the company’s visibility — all of Sheraton’s hotels will feature the program by the end of 2011.

The company provides personal online fitness advice, coaching, food and lifestyle tips from its website CorePerformance.com, based on the experience of the company with professional athletes.

With travelers frequently citing fitness centers as among the most important hotel amenities, it’s no surprise that chains are constantly competing to create the most attractive workout propositions.

In 2006, Hilton signed a landmark deal with Precor which was later extended globally — guests in many Hilton facilities today have access to the branded fitness centers.

Luxury hotel chain Fairmont, meanwhile, has a deal with Adidas to provide members of its President’s Club program with rental workout gear when they check in to Fairmont properties.

Marriott-owned chain Renaissance has gone even further, this year creating a boutique hotel brand themed around fitness called Renaissance ClubSport, which operates two properties in California.